Volumes

by publication dates
July 2017 (1)
December 2016 (2)
November 2016 (1)
October 2016 (1)
February 2016 (1)
December 2015 (4)
September 2015 (2)
July 2015 (1)
March 2015 (1)
December 2014 (3)
July 2014 (2)
May 2014 (1)
December 2013 (4)
October 2013 (1)
March 2013 (1)
January 2013 (1)
December 2012 (6)
October 2012 (2)
July 2012 (1)
January 2012 (1)
December 2011 (3)
November 2011 (1)
October 2011 (1)
September 2011 (1)
August 2011 (1)
May 2011 (1)
March 2011 (1)
February 2011 (1)
August 2010 (1)
June 2010 (2)
May 2010 (2)
April 2010 (1)
March 2010 (2)
February 2010 (2)
December 2009 (1)
October 2009 (6)
September 2009 (2)
August 2009 (2)
July 2009 (1)
April 2009 (1)
February 2009 (7)
January 2009 (5)
December 2008 (1)
October 2008 (1)
September 2008 (4)
August 2008 (4)
June 2008 (1)
May 2008 (1)
April 2008 (1)
February 2008 (4)
January 2008 (3)
December 2007 (5)
November 2007 (2)
August 2007 (1)
June 2007 (3)
May 2007 (4)
March 2007 (3)
February 2007 (1)
January 2007 (1)
November 2006 (1)
October 2006 (1)
September 2006 (3)
June 2006 (1)
May 2006 (1)
April 2006 (2)
February 2006 (2)
January 2006 (2)
December 2005 (7)
November 2005 (1)
October 2005 (5)
September 2005 (1)
June 2005 (1)
April 2005 (3)
March 2005 (16)
February 2005 (4)
January 2005 (6)
December 2004 (2)
November 2004 (7)
October 2004 (1)
September 2004 (12)
December 2003 (4)
October 2003 (37)
March 2003 (13)
December 2002 (7)
December 2001 (7)
December 2000 (34)
October 1999 (21)
November 1998 (6)
October 1998 (18)
December 1997 (28)
April 1997 (7)
October 1996 (13)
September 1996 (1)
April 1996 (9)
October 1994 (8)
July 1994 (9)
December 1993 (1)
December 1992 (26)
January 1992 (9)
February 1991 (9)
December 1990 (3)
December 1989 (8)
October 1989 (9)
December 1988 (9)
December 1987 (11)
December 1986 (11)
December 1985 (10)
June 1985 (11)
November 1984 (12)
January 1984 (18)
July 1983 (1)
December 1982 (12)
May 1982 (9)
November 1981 (12)
November 1980 (12)


JNAFS

15

Scott M. Grant

Centre for Sustainable Aquatic Resources, Marine Institute of Memorial University of Newfoundland
P. O. Box 4920, St. John's, Newfoundland, Canada  A1C 5R3

Publication (Upload) date: 15 May 2006

GRANT, S. M. 2006. An exploratory fishing survey and biologial resource assessment of Atlantic hagfish (Myxine glutinosa) occurring on the Southwest slope of the Newfoundland Grand Bank. J. Northw. Atl. Fish. Sci., 36: 91–110. doi:10.2960/J.v36.m548

Abstract

An exploratory Atlantic hagfish (Myxine glutinosa) survey was conducted on the southwest slope of the Newfoundland Grand Bank during autumn 2002 to collect samples for a biological resource assessment and investigate the selective properties of baited 227-litre traps with 12.7, 13.5, and 14.3 mm (1/2", 17/32", and 9/16") diameter escape holes. Atlantic hagfish were found to exhibit a juvenile hermaphroditic stage. Female Atlantic hagfish exhibited a total length (TL) at first, 50%, and 100% sexual maturity of 354, 378, and 440 mm, respectively. The testis was small and rudimentary showing no sign of maturation in the form of enlarged lobules in 350 hagfish examined within a size range of 195–638 mm TL. Each sexually mature female possessed a single clutch of developing ovoid eggs of similar size and 28% possessed both developing and degenerating eggs. Degenerating eggs were limited to the early stage of the reproductive cycle among females with developing eggs that were <12 mm in length. Examination of females with large (≥14 mm) eggs revealed a positive correlation (r2 = 0.61) between fecundity and total body length, however, the reproductive potential was low (11–38 eggs per female). Recent evidence of a seasonal reproductive cycle and current findings of a bimodal egg length-frequency distribution and the presence of several females with postovulatory follicles in a single point in time sample suggest there may be up to three synchronized spawning events per year on the Grand Bank. The intermediate status of the Grand Bank population with respect to maximum length, size at first attainment of sexual maturity, and body markings relative to populations in the eastern North Atlantic and continental shelf and slope waters of the eastern US corroborates the existence of clinal variants. Catches in control traps indicate a clear tendency for the average individual hagfish body size to increase with depth over a 146–664 m depth range. A length-weight relationship indicated the minimum marketable body weight coincides with a total length of 410 mm. The 14.3 mm trap consistently captured the lowest percentage of undersized (<410 mm TL) individuals. Studies suggest few hagfish will survive when released, therefore it is recommended Grand Bank fishermen be encouraged to use traps with 14.3 mm escape holes or larger.

Key words: escape holes, hagfish, maturity, reproduction, survey, traps

PDF
Actions: E-mail | Permalink |

Related Files